Many modern radio receivers are designed to operate in the digital domain when performing a final frequency conversion step (also known as I-Q demodulation) wherein a signal at a radio frequency (RF) or intermediate frequency (IF) is converted into a complex baseband signal. Performing this frequency conversion step in the digital domain has a number of benefits in that the digital signal paths between the real (I) and imaginary (Q) parts of the signal are exactly matched and their phase relationship does not deviate from an ideal quadrature relationship.
In contrast to this approach, some other types of radio receivers perform the frequency conversion step in the analog domain. Operating in the analog domain can lead to the I-channel signal path and Q-channel signal path having different characteristics and the phase relationship between the real and imaginary parts of the signal deviating from the ideal quadrature relationship. Both of these effects can lead to errors being present in the demodulated signal and these errors can sometimes be difficult to correct or may even be uncorrectable. Nevertheless, a radio receiver performing I-Q demodulation in the analog domain can provide certain benefits such as a wider bandwidth and fewer processing steps in a digital domain signal processing portion of the radio receiver. In view of such benefits, particularly in terms of the wider bandwidth, it is desirable to provide for improved error detection and error correction circuitry in these types of radio receivers.